You might want to research Schutzhund sport clubs in Canada. The Boxer breeders who are involved here in the US usually leave the tails intact. If you are in line to get a puppy you have the option of having the tail cropped when the litter is born. More breeds, like Boxers and Rotties are able to train at these clubs. Before it was mainly the GSD.
You would want to work closely with a breeder who would only place a puppy that was suitable for a family dog.